1. Field of the Invention
The present invention relates to a core of a motor. More particularly, the present invention relates to a laminated core of a motor having a structure which promotes insulation coating on the surface of the laminated core manufactured by laminating thin steel sheets.
2. Background Art
In general, a core used for a stator of a motor has a plurality of teeth formed radially on the inner circumferential surface or the outer circumferential surface of a rounded base core. A coil is wound on each of the teeth, and a contact portion between the coil and the teeth must be insulated electrically.
Various methods for such an electrical insulation have been proposed, and there is a representative method for connecting an insulator which is made with a plastic injection molded article to the upper part and the lower part of a laminated core and winding a coil on a teeth part.
As another method, Korean Patent Laid-open No. 10-1994-0003141 and Japanese Patent Laid-open No. 09-285078 disclose technology for coating the surface of the laminated core with insulating powder to insulate the surface of the core. However, in case that insulating powder or other insulating material is coated on the laminated core, there is a problem in that the insulating material is not uniformly coated on the teeth of the laminated core or at the edge of the inner circumferential surface but is massed in a lump or the coated material is peeled when the coil is wound on the laminated core.
In the meantime, in case of using an insulating plastic insulator, because the width of the insulator which covers tooth ears, namely, teeth end portions is larger than the width of the teeth end portions of the core even though a coil is wounded on the teeth, the wound coil is not separated from the teeth end portions. However, in case that a coil is wound on the teeth portions of the laminated coil which is insulating-coated, because the width of the tooth ears is not secured, the wound coil protrudes out of the tooth ears and gets in contact with a rotor inside the stator, and hence, it causes malfunction of a motor due to generation of withstand voltage.
In order to solve the above problems, the inventors of the present invention propose a laminated core for a motor having a new structure.